The Jacobsen Method
The Jacobsen germinator mainly consists of a germination plate being temperature-conditioned by means of the water basin below. The water bath is equipped with an automatic temperature control.
The germination spirals being equipped with a paper wick and a paper substrate are placed on the germination plate. The wick is being led through slots in the germination plate and reaches into the water bath below, thus supplying the required humidity and the desired temperature to the paper substrate. The circular filter papers are covered with a transparent cover dome to provide the air humidity being required for the germination. A little hole in the upper end of that dome ensures sufficient supply of fresh air and minimum evaporation at the same time.
Units being executed with active cooling allow day-night temperature alternation, as well as any temperature profile.
The Rodewald Method
Rodewald germinators are mainly consisting of a tub being filled with silica sand, which is hanging in a temperature-conditioned water basin for temperature conditioning and moistening.
The Rodewald method is particularly suitable for vegetable or forest seed due to the adjustable low humidity and the inferior tendency to fungal growth. The seed is deposited on filter papers on the sand. A water channel being integrated in the sand insertion tub with adjustable level regulation gives moisture to the seed via wicks in the sand and the capillary effect of the sterilized crystal silica sand.
An acrylic glass cover avoids drying-out of the sand. The glass cover can be steplesly opened for ventilation. A surrounding groove avoids dripping of the condensate water into the sand.